Predominant sensory ataxic neuronopathy showing marked improvement after resection of a thymoma followed by intravenous immunoglobulin therapy.

A 64-year-old man was admitted to our hospital because of difficulty in walking and numbness in his lower extremities. Upon investigation, the patient was diagnosed as having predominant sensory ataxic neuronopathy associated with thymoma. Surgical resection of the thymoma followed by intravenous immunoglobulin therapy resulted in marked improvement of the patient's clinical symptoms; therefore immunological mechanisms related to the presence of the thymoma were suspected to underlie the neuropathy in this patient. We did not find any previous reports of an association of sensory ataxic neuronopathy with thymoma, even after a thorough search of the literature.